Electroextraction of heavy metals from wastewater for the protection of natural water bodies from pollution
Journal Title: Восточно-Европейский журнал передовых технологий - Year 2018, Vol 1, Issue 10
Abstract
<p>The most promising methods of eluates recycling are electrolysis and electrodialysis. It is possible to obtain metals and purified regeneration solutions for repeated regeneration in case of application of electrochemical methods. The processes of electrolysis of solutions of cadmium and zinc sulfates and chlorides in electrolysers of different types were explored, the influence of conditions of electrolysis on effectiveness of extraction and separation of metals, obtaining inorganic acids for repeated usage in regeneration processes was determined.</p><p>Single- and double-chamber electrolysers, in which cathode was made of stainless steel and titanium anode was covered with ruthenium oxide, were used. Cathodic and anodic areas in double-chamber electrolysers were separated by the anion exchange membrane MA-41.</p><p>Solution of cadmium sulfate or of zinc sulfate was found in the cathodic chamber in double-chamber electrolysers. Solution of sulfuric acid with concentration of 50 mg-equiv./dm<sup>3</sup> was in the anodic chamber.</p><p>It is recommended to carry out electrolysis for two hours when using a single-chamber electrolyser at a voltage of 5 V with the purpose of removing cadmium from sulfuric acid solution and reusing regeneration solution of sulfuric acid. Almost complete removal of cadmium ions and concentration of sulfuric acid in anolyte is achieved in case of using a double-chamber electrolyser. However, in terms of power saving, release of cadmium should be performed in single-chamber electrolysers.</p><p>However, it is recommended to perform zinc removal from eluates in double-chamber electrolysers. In this case, zinc ions are almost completely removed within four hours at voltage of 25 V. The maximum current efficiency is 42‒80 %.</p>Conditions of separation of zinc and cadmium in the eluate are associated with acidity of the solutions. A stage-by-stage removal of metals – cadmium followed by zinc, is observed during electrolysis of the mixture of cadmium and zinc chlorides in a single-chamber electrolyser. Current efficiency of metals is 30–68 %. In the case of electrolysis of a mixture of zinc and cadmium sulfates, only cadmium (В=100 %) is removed from the solution, while zinc ions completely remain in solution. Zinc is released only at the transfer of the electrolyte to a double-chamber electrolyser
Authors and Affiliations
Nikolai Gomelia, Ganna Trokhymenko, Olena Hlushko, Tatiana Shabliy
Keywords
Related Articles
- EP ID EP527814
- DOI 10.15587/1729-4061.2018.123929
- Views 72
- Downloads 0
Twostage treatment of solid waste leachates in aerated lagoons and at municipal wastewater treatment plants
<p>The two-stage technology of treatment of the leachates of the municipal solid waste (MSW) dumps in aerated lagoons and at municipal wastewater treatment plants (WWTP) has been studied. The study objective was to devel...
Reduction and optimal performance of acyclic adders of binary codes
<p>The conducted studies have established the prospect of increasing productivity of computing components, in particular, combinational adders, based on applying principles of computation of digital signals of the acycli...
Determining the maximally permissible values for the indicators of insulation of sealed entrance bushings with a voltage of 110 kV using the method of minimal risk
<p>A method for determining the maximally permissible values for the indicators of insulation of high-voltage oilfilled entrance bushings that ensure the minimal risk value has been proposed. The proposed method differs...
Development of the method for modeling the propagation of delays in noncyclic train scheduling on the railroads with mixed traffic
<p>The main goal of present study is to develop a method for modeling delay propagation in non-cyclic train scheduling on a railroad network with mixed traffic. This will make it possible to explore the dynamics of delay...
Astabilizing system for butter pastes based on the dry concentrates of milk protein
<p>The composition of the stabilizing system for butter pastes based on dry concentrates of milk and whey proteins has been substantiated; that would help reduce the deficiency of protein in the diet of modern human and...